Typically, respiratory therapy is delivered in the form of a respiratory mask or mask system positioned between a patient and apparatus providing a supply of pressurized air or breathing gas. Mask systems in the field of the invention differ from mask systems used in other applications such as aviation and safety in particular because of their emphasis on comfort. This high level of comfort is desired because patients must sleep wearing the masks for hours, possibly every night for the rest of their lives. In addition, therapy, compliance can be improved if the patient's bed partner is not adversely affected by the patient's therapy and wearing of the mask generally.
Mask systems typically, although not always, comprise (i) a rigid or semi-rigid portion often referred to as a shell or frame, (ii) a soft, patient contacting portion often referred to as a cushion, and (iii) some form of headgear to hold the frame and cushion in position. If the mask system does include multiple components, at least some assembly and adjustment may be required, which can be difficult for patients who may suffer from lack of dexterity, etc. Further, mask systems often include a mechanism for connecting an air delivery conduit. The air delivery conduit may preferably be connected to a blower or flow generator.
A range of mask systems are known including nasal masks, nose & mouth masks, full face masks and nasal prongs, pillows, nozzles & cannulae. Masks typically cover more of the face than nasal prongs, pillows, nozzles and cannulae.
Some respiratory masks cause discomfort or are difficult to seal on some patients. Comfort and seal may be particularly troublesome in the nasal bridge region. Other portions of the mask system including but not limited to the forehead support and headgear clips may cause discomfort or cause skin breakdown (e.g. ulceration, skin marking, irritation, redness, etc).